1. Field of the Invention
The present invention relates to distributed amplifier logic designs and, more particularly, to logic designs utilizing differential input and output pairs for each logic gate in combination with input and output inductive transmission lines and neutralizing capacitance elements to increase the operating speed of such logic devices.
2. Description of the Prior Art
In the design of high speed logic circuits there is an on-going need for wideband amplifiers. Wideband amplification has been provided in the past by using a distributed amplifier design. One such design is described in the article entitled "A DC-12 GHz Monolithic GaAsFET Distributed Amplifier" by E. W. Strid et al. appearing in IEEE Transactions on Microwave Theory and Techniques, Vol. MTT-30, No. 7, July 1982 at pages 969 et seq. In the Strid et al. article, a multi-stage FET amplifier is described that uses an inductive input, an inductive output (the input and output being the respective gate and the drain terminals of the GaAsFET device).
In a distributed arrangement such as the Strid et al. design mentioned above, there remains an intrinsic capacitance between the gate and the drain of each amplifying device (denoted C.sub.gd). This intrinsic capacitance is problematic in that it results in the input of each stage being coupled to its associated output, as well as for each stage to be coupled together. Therefore, the operation of any particular stage is impacted by all previous stages as well as all subsequent stages in the multi-stage design. This interrelationship complicates the design of a multi-stage arrangement and has limited the application of distributed techniques to amplifiers. Thus, a need remains in the art to expand the application of distributed techniques to logic circuit designs.